Automotive applications typically using an air pump, specifically a turbine, supercharger or exhaust driven turbocharger, include gasoline, natural gas or diesel internal combustion engines, benefit from the use of an air bypass valve. Other automotive applications also include fuel cells and fuel reformers, both requiring large volumes of air, and often supplied by a turbine pump and benefit from an air bypass valve. These bypass valves include a solenoid device that has armature and stator poles. FIGS. 1A to 1L show some conventional shapes for basic magnetic cores. For example, the core 10 of FIG. 1A is a rod or cylindrical core, the core 12 of FIG. 1B is an E-core, the core 14 of FIG. 1C is a bar or I-core, the core 16 of FIG. 1D is a toroid or doughnut core, the core 18 of FIG. 1E is a C or U-core, the core 20 of FIG. 1F is a planar core, the core 22 of FIGS. 1G and 1H is a RM core, the core 24 of FIGS. 1L and 1J is a P core, and the core 26 of FIGS. 1K and 1L is an EDT core.
Combinations of core shapes create the various prior art solenoid configurations, such as E-E, EI, C-C, UI, EP, EEM, ER, and ETD. Armature-stator configurations can either be extrusions of the two dimensional representative shape or axis-symmetric revolutions around an axis. FIGS. 2A to 2D show some conventional armature-stator shapes. In particular, FIG. 2A shows an armature 30 and a stator 32 with a central working gap, FIG. 2B shows an armature 34 and a stator 36 with conical profile poles, FIG. 2C shows an armature 38 and a stator 40 with a ⅔ located working gap, and FIG. 2D shows an armature 42 and a stator 44 with a ⅓ located working gap. Although these configurations are useful, there can be improvements in the armature-stator configuration.
Thus, there is a need to provide an improved configuration of armature and stator pole configurations in a solenoid device such that the geometries of the armature and stator poles can be adjusted to various forces as a function of stroke characteristics.